Stewart Dundee-Hooper was born on 18 September 1893, the only son of Harry Dundee-Hooper and Agnes Maria Hooper. He joined the Royal Navy as a Cadet on 15 September 1906. He was promoted to Midshipman on 15 May 1911 and was appointed to the cruiser HMS DRAKE on 5 December 1911. He was appointed to the battleship HMS CONQUEROR on 28 February 1913. He was promoted to Sub Lieutenant on 15 April 1914, and on 6 May 1914, Stewart Dundee-Hooper was appointed to the battleship HMS BELLEROPHON. He was promoted to Acting Lieutenant on 19 September 1915.

He was appointed to HMS DOLPHIN 'for Submarines' on 1 December 1915 and on 10 February 1916, he joined HMS C7 as First Lieutenant. On 1 April 1916, he was appointed to HMS E4 as First Lieutenant. E4 was sunk with all hands, following a collision with HMS E41 off Harwich on 15 August 1916.